Tony Buttler came to talk to fellow Members on October 9th where he
introduced by our Chairman, Chris Roberts. Tony joined High Duty Alloys
in 1974 as a metallurgist and developed a great interest in military
aircraft, in particular their design and development. He went on to
take a Masters Degree in Archives and Library Studies at Loughborough
University, and since 1995 he has been a freelance aviation historian.
He has just completed his thirty-third major book, is a member of the
Royal Aeronautical Society’s Historical Group Committee, lectures
extensively and has written many specialist books and magazine articles
Tony explained the sources for today’s talk and for his many books on British military aircraft projects. Three-view general arrangement drawings are often the only surviving evidence for many unbuilt designs. If a project was proposed against a government specification or offered as a private venture, these drawings would become part of a brochure which would provide details of the structure, give size and weight data, list the weapons and equipment it might carry and give the estimated performance. Major proposals would be accompanied by wooden scale models. For many years these unbuilt designs remained secret because, even if they were rejected, they still represented the state of the art. However, over time classifications have been removed and it is possible see the work of the British aircraft industry post World War 2.
In his talk Tony looked at Hawker Aircraft Ltd’s jet
fighter and bomber designs produced prior to the V/STOL era. The talk
also touched on some designs that were built, and on the large strike
aircraft proposed to the OR.339 Canberra Replacement requirement of
1958. He also made references to Hawker’s rival, Supermarine, whose
projects ran parallel to those of the Sydney Camm team at Kingston.
Tony started his review with the piston engined P.1030, a 500 mph Tempest development with a 24 cylinder, 3,000 hp Rolls-Royce (R-R) Eagle engine.
This was Hawker’s last word in piston engined fighters powered by R-R’s last major piston engine. Supermarine also proposed the Eagle for their Type 391. One late Hawker piston project that Tony had not been able to track down is the twin boom, twin-RR Griffon-powered P.1037 fighter of 1944. (Does anybody out there have any drawings or reports? - please contact the Editor).
Moving on to the jets, the first Hawker design was the P.1035 ‘Jet Fury‘, which married the elliptical Fury wings to a new fuselage with a R-R Nene engine, wing root intakes and short bifurcated jet pipes. This was developed into the P.1040 which had straight tapered wings. A prototype flew 1947 and matured into the Sea Hawk Fleet Air Arm fighter. In 1950 the P.1040 became the P.1072 when it was fitted with an Armstrong-Siddeley (A-S) Snarler rocket motor to investigate the mixed power plant concept.
During the second half of the 1940s Hawker began to examine the effects of wing sweepback by fitting such wings to a P.1040 type fuselage resulting in the P.1047 project and the P.1052. The P.1052 retained the straight tail. Two were built, the first, VX272, flying in November 1948. The next stage was to sweep all of the flying surfaces so the second P.1052, VX279, was rebuilt as such, with a single tail pipe, to become the P.1081 which first flew in June 1950. Sadly it was soon lost in a fatal crash. Supermarine’s equivalent to this was the Type 510, an Attacker with swept wings and tail, which flew at the end of 1948. It was modified to become the Type 535 leading to the Type 541 Swift.
Amongst the Seahawk variants were two offered in March 1947 as interim interceptors, the P.1062 and P.1068. The former had swept wings, the latter straight wings. Both had the same fuselage, R-R Tay engine - a development of the Nene - a T-tail and a straight through jet pipe.
Aside from what Tony considered the main line of Hawker fighter development came the 1946 P.1048, similar in layout to the Messerschmitt Me 262, with straight wings, a pair of R-R AJ.65 engines (later named Avon), with two 30mm Aden cannon. Also in 1946 the P.1051 medium naval bomber emerged. Powered by two R-R AJ.65s, it resembled a scaled up P.1040.
In January 1947 the Air Ministry issued Specification F.43/46 for a new day interceptor to replace the Meteor. Gloster, Hawker and Supermarine submitted proposals; Hawker, the P.1054. The forward fuselage housed two AJ.65s, below and beside the cockpit, and a massive 4.5in recoilless gun. The P.1054 was expected to achieve Mach 0.93 in level flight but the weapon, with a rotating chamber holding half a dozen shells, was complex and unwieldy, the barrel itself being 10ft long.
Technology in the late 1940s was advancing very quickly, with swept and delta wings, more powerful engines, new materials and the first guided weapons, so F.43/46 was soon outdated and in February 1948 was superseded by F.3/48. A new round of design submissions followed and one of at least three from Hawker was the P.1064. This low wing, all swept design powered by two R-R AJ.65s had the 4.5in gun or four Adens. At this stage the Ministry favoured the proposal for the new day fighter from Gloster which eventually became the Javelin night fighter. Hawker had been improving its day fighter proposals principally by reducing frontal area which, with two AJ.65s, was too large so projects with a single engine plus a rocket motor were schemed.
The night fighter requirement, F.44/46, resulted in orders for prototypes to Gloster and de Havilland for the GA.5 and DH110, which matured into the Javelin and Sea Vixen. Hawker’s proposal, the P.1057, was not pursued. This was an all swept, two-seater with two fuselage mounted AJ.65s, armed with four Adens.
Hawker’s day fighter effort, using the flight experience gained with the P.1052 and P.1081, culminated in the P.1067 which in 1948 featured swept wings, a delta T-tail and a nose intake. With a single R-R AJ.65, now named Avon, it was expected to achieve 710mph at sea level and would be armed with four Adens. To provide more room in the forward fuselage a solid nose and wing root intakes were substituted and a wooden mock-up of this configuration was built. Subsequently a swept tailplane was mounted low on the fin. The prototype, WB188 flew in July 1951.
Meanwhile at Supermarine the Swift had been ordered as an insurance against the failure of the Hunter but was itself suffering from all sorts of handling problems. Although a disaster as a fighter it did later achieve some success as a low level reconnaissance aircraft in its Mk 7 form.
The Hunter could easily exceed Mach 1 in a shallow dive but was subsonic in level flight. To confer level supersonic speed the P.1083 project of 1951 was developed. The Hunter’s 40° swept wing was replaced with a new one of 50° sweep, and the R-R Avon was reheated to give a maximum thrust of 17,750 lb. A prototype was ordered and was due to fly in late summer 1953 but the project was cancelled in July of that year. The unfinished P.1083 prototype was rebuilt as the P.1099, the prototype for the Hunter F.Mk.6 with the uprated R-R Avon 200-series engine. Supermarine’s rival was the Type 545, the prototype of which was also cancelled before completion.
Many Hunter variants were studied including the delta winged P.1091 of October 1951. The 1957 P.1128 was a six-seat executive jet in which Hunter wings and tail were fitted to a new fuselage with two rear mounted Bristol-Siddeley Orpheus engines. A significant Hunter variant was the two-seat P.1101.
Early in the Hunter’s career the 3rd prototype flew with four dummy DH Blue Jay (later named Firestreak) air-to-air missiles under its wings. From 1956 there was a concerted effort to see if the aircraft could be equipped with two such weapons and the new Green Willow AI.Mk.20 radar. The modified airframe with an extended nose was the P.1109. The drag from carrying two missiles was compensated by fitting a more powerful 11,250lb thrust Avon RA24. The Government-funded Hunter-Firestreak development programme was cancelled in May 1956, but it was continued by Hawker as a private venture. Three Mk.6 airframes were fitted with long noses but only XF378 carried the two Blue Jays along with the AI.20 radar installation. XF378 flew in September 1956 and attended the 1957 Farnborough Show. Radar unreliability led to the discontinuation of the project.
In 1951 Hawker had begun to examine fighters with true supersonic capability and in due course produced several project designs, either as Hunter developments or all new layouts. The P.1090 of August 1951 was a Hunter development powered by a DH Gyron engine giving well over 20,000lb of thrust with reheat. It had a 50° swept wing and four Adens. The P.1092 blended delta, two-seat all-weather fighter of November 1951 was powered by a single reheated Avon and was expected to reach Mach 1.5 at 36,000ft and had four Adens mounted in the wings. The Gloster Javelin dominated RAF planning at this time and the P.1092 was not adopted.
The February 1952 the P.1093 supersonic blended delta all-weather fighter was drawn with a single Avon RA.14 or DH Gyron fed by a nose pitot intake. It had six wing-mounted Adens. A Hunter development from 1953 was the P.1100 supersonic ‘thin-wing’ Hunter with an RA.24 Avon and two rocket motors in the trailing edge wing roots. Mach 1.5 was predicted for this fighter with two Adens, two under-wing Firestreaks and an AI.20 radar. The December 1954 P.1104 was a large, tailed-delta Mach 2 fighter with two under-wing reheated DH Gyron Junior engines, and two Adens under the cockpit.
In 1952 Specification ER.134T was raised to fund a research aircraft capable of flying at Mach 2 for 10 minutes. Several designs were submitted by various companies and the competition was won by the Bristol 188. Hawker offered the P.1096 and P.1097, both to be powered by an R-R RB.106R engine. The P.1096 was predicted to be capable of Mach 2.35 at height, but the P.1097 fell a little short at Mach 1.9. Camm was never really interested in designs produced solely for research but always looked for production types, so these two proposals were examined closely to discover any fighter potential, the P.1097 being drawn with four Adens underneath the cockpit.
In 1954 Specification M.148T was issued for a new tactical nuclear strike aircraft designed to operate from aircraft carriers. The Hawker submission, by Camm under duress because he didn‘t like it, was the P.1108 powered by four relatively small R-R RB.115 engines. The weapons included conventional bombs and the Green Cheese tactical nuclear bomb. The design was rejected, in part because of Hawker’s current workload on the Hunter and a consequent shortage of manpower. The winner from Blackburn became the Buccaneer.
In 1955 the Air Ministry issued specification F.155T for a very capable high-altitude all-weather supersonic interceptor and Hawker was one of seven firms to respond with its Mach 2 P.1103. This design incorporated a chin intake for its DH Gyron engine, a large nose radome and two seats. Auxiliary rocket motors could also to be fitted. P.1103 was to carry Red Hebe air-to-air missiles, but the main weapon for F.155T was the huge 1,330lb Vickers Red Dean radar-guided air-to-air missile. Fairey Aviation won the competition but its massive delta wing fighter was cancelled by the 1957 Defence White Paper.
After rejection the P.1103 was remodelled as the P.1116 long range strike fighter with a smaller wing and reduced sweepback. In mid-1956 the P.1116 was redesigned as the P.1121 single-seat fighter. The Hawker Siddeley Group board approved the construction of a private venture prototype. However, the aircraft was never ordered by the RAF and the prototype was only about 50% complete when work on it was halted in 1958. The P.1121 is probably the most important of Hawker’s ‘lost’ designs. It was to be powered by a DH PS.26 Gyron engine giving 23,800lb thrust with reheat, and was to be armed with two Red Top air-to-air missiles (the improved version of Firestreak), rocket projectiles and two Adens.
There were further developments of the P.1121, including the P.1123 Mach 2 tactical nuclear bomber of January 1957 powered by a Rolls-Royce Conway engine. This was quickly followed by the P.1125 of March 1957, Hawker’s response to the initial ideas now appearing for a new requirement, GOR.339, for a ‘Canberra Replacement’. The P.1125 was a development of the P.1121 with similar aerodynamic qualities. Its was powered by a pair of R-R RB.133s, a supersonic version of the RA.24 Avon, giving a capability of Mach 1.3 at sea level and Mach 2.32 at 36,000ft. The weapons bay could accommodate conventional bombs or gun or rocket packs, while the large nuclear bomb would be carried semi-recessed under the fuselage.
For the full GOR.339 design competition, Hawker refined the P.1125 into the P.1129 strike aircraft which was submitted in January 1958. The P.1129 was much bigger than the P.1121. Powered by two R-R RB.142 Medway engines each giving 22,500lb of thrust with reheat its calculated maximum speeds were Mach 1.28 at sea level and Mach 2.3 above 36,000ft. Its weapon bay could house rockets or four 1,000lb bombs, a Red Beard nuclear store would go underneath the fuselage, and more rockets or another four 1,000lb bombs would go on wing pylons. The P.1129 was rejected in favour of the English Electric P.17 and the Vickers (Supermarine) Type 571, that were eventually blended to give the BAC TSR.2. During the GOR.339 design assessment the Hawker Siddeley Group had been criticised for a lack of direction. In fact two projects, the Hawker P.1129 and the Avro 739, were in competition with one another. A company policy change in July put Sir Sydney Camm in overall charge of a Group design team. The P.1129 was modified to incorporate certain features from the Avro 739. This ‘P.1129 Development’ was submitted in a Hawker Siddeley Group brochure in November 1958. But it was too late; the BAC design remained the choice only to be cancelled in 1965 after a few flights.
The rejection of the P.1121 and P.1129 brought this line of Hawker aircraft development to a close but a new line had already been started in the P.1127 V/STOL project, which led to the Harrier and all its variants. Kingston survived for another 30 or so years as Hawker Aircraft Ltd, Hawker Siddeley Aviation and British Aerospace, but sadly, Supermarine faded away….
The vote of thanks was given by Editor Chris Farara who, as keeper of the Hawker archive at the Brooklands Museum, had assisted Tony in his research for many years. He thanked the speaker for his excellent, well illustrated talk.